Susceptibility near a critical point. Consider a ferromagnetic system with n spins per volume, where each spin has magnetic moment u. There is an effective B-field from the mean magnetization, BE = AM. However, now there is an external field, Bo, such that the total effective field is B = AM + Bo. (a) Assume B0 = 0 (no external field). Near the critical point, the magnetization will have the form M x t- telP. Calculate te and B. (b) The magnetic susceptibility x = dM/dB near the critical point will obey x x (t-T.)". When t >T, M and B are both very small, so x = M/B also works. Calculate y.

Susceptibility near a critical point. Consider a ferromagnetic system with n spins per volume, where each spin has magnetic moment u. There is an effective B-field from the mean magnetization, BE = AM. However, now there is an external field, Bo, such that the total effective field is B = AM + Bo. (a) Assume B0 = 0 (no external field). Near the critical point, the magnetization will have the form M x t- telP. Calculate te and B. (b) The magnetic susceptibility x = dM/dB near the critical point will obey x x (t-T.)". When t >T, M and B are both very small, so x = M/B also works. Calculate y.